Combination depth stop and gauge assembly for a dental drill

ABSTRACT

The assembly includes a first surface adapted to be secured to a drill housing to serve as a reference plane and a second surface which serves as a seat to control the cut taken. A pair of screws couple through the reference member to carry the seat either towards or away from the reference plane, depending upon their manners of rotation. Both surfaces are apertured to accept a drill bit extending from a spindle in the housing, with the extension of the bit through the aperture in the seat controlling the depth of cut possible.

Oct. 1, 1974 1 COMBINATION DEPTH STOP AND GAUGE ASSEMBLY FOR A DENTALDRILL Bruce T. Michnick, 33 Cherry Dr., Plainview, NY. 1 1803 Filed:Apr. 9, 1973 Appl. No.: 348,921

Inventor:

U.S. Cl. 32/27 Int. Cl. A610 1/10 Field of Search 32/67, 26, 27, 49, 29,

[56] References Cited UNITED STATES PATENTS 1,377,288 5/1921 Soresi32/26 3,346,959 10/1967 Fridge 32/67 FOREIGN PATENTS OR APPLICATIONS371,696 4/1932 Great Britain, 32/31 Primary ExaminerRobert PeshockAttorney, Agent, or FirmCharles 1. Brodsky [57] ABSTRACT The assemblyincludes a first surface adapted to be secured to a drill housing toserve as a reference plane and a second surface which serves as a seatto control the cut taken. A pair of screws couple through the referencemember to carry the seat either towards or away from the referenceplane, depending upon their manners of rotation. Both surfaces areapertured to accept a drill bit extending from a spindle in the housing,with the extension of the bit through the aperture in the seatcontrolling the depth of cut possible.

COMBINATION DEPTH STOP AND GAUGE- ASSEMBLY FOR A DENTAL DRILL.

FIELD OF THE INVENTION This invention relates to depth stop and gaugeassemblies for drill constructions, in general, and to such assembliesfor use in-root canal dentistry, in particular.

SUMMARY OF THE INVENTION As will become clear hereinafter. the assemblyof the invention is especially attractive in that it affords a positivemeans of controlling the depth of cut made by a dental drill. Inoneem'bodiment, an annular disk is employed, adapted for securement to astandard contraangle by a lock-screw collar which maintains the burr andits spindle holder in correct alignment. The annular disk also includesa pair of threaded holes, through which a pair of adjustable screws fitto mate with a second pair of aligned holes on an apertured plate. Thesescrews carry the plate either towards or away from the disk dependingupon their manner and degree of screw rotation. With the aperture of thedisk and the opening of the plate both being in corresponding alignmentto accept the burr of the spindle, the plate then acts as a seat tolimit the penetration of the bit into a tooth being prepared. Theprecisedepth of cut to be.takenas determined from a grid X-ray, forexample-can be preset by adjusting the separation between the bearingsurface plate and the reference surface disk until the burr protrudesthrough both by the desired amount.

BRIEF DESCRIPTION OF THE DRAWING DETAILED DESCRIPTION OF THE DRAWING Inthe drawing, reference numeral represents a contraangle dental drill ofa construction which is oftentimes used with a straight hand piece inworking in the back areas of a patients mouth. For purposes of thepresent discussion, the contraangle 10 incorporates a spindle 12 whichis geared to rotate and carry a drill bit or burr l4, usually ofstandardized length. A lock screw collar 16 bears against the spindle 12to align and secure it substantially co-axially with the dental burr.

In accordance with one embodiment of the invention, however, thelockscrew collar 16 also serves to align and secure a depth stop andgauge assembly 20 to the contraangle 10, More specifically, an annulardisk 22 of appropriate configuration is positioned intermediate thespindle 12 and the collar l6,such that adjustment of the collar tosecure the spindle in place also serves to bear the annulardisk 22against the contraangle housing. An apertured plate 24 also forms a partof the depth stop and gauge assembly 20, and is affixed with the annulardisk 22 by means of two or more .fas-. teners-screws 25,26, for example.In particular, these fasteners fit through threaded holes 50,52 in theannular disk 22 and in the apertured plate 24 in a manner such that thedisk 22 serves to carry the plate 24. With the pairof threaded holes50,52 arranged co-axially with the-major dimension of both the annulardisk 22 and the apertured plate 24and equally spaced on opposite sidesof the holes therein, rotation of the screws 25,26 in the same directionwill carry the plate 24 towards or away from the disk 22. Thus, byrotating the screws 25,26 clockwise, the apertured plate 24 caneffectively be tightened by the screws towards the annular disk 22,whereas a counter-clockwise rotation of the screws 25,26 can loosen theapertured plate 24 away from the annular disk. With standardized lengthburrs protruding from the spindle through the holes in both the disk 22and the plate 24, these screw rotations can effectively vary theamount'by which the burr extends beyond theapertured plate.

.As will be readily apparent, theapertured plate 24 can serve as abearing or stop" surface to limit the depth to which the burrextendsinto a tooth being drilled, The annular disk 22, in this manner. servesas a reference plane, with respect to which the apertured plate 24 isadjusted to vary the depth of penetration desired. As will be seen, thedepth of, penetration equals the sumof the length the burr l4 protrudespast the spindle 12 together with the thickness of the lock screw collar16, less the length between the annular-disk 22 and the apertured plate24.

In operation, an X-ray grid of the tooth being worked upon can beanalyzed to determine the depth of penetration desired. The depth stopgauge assembly 20. c a n then be attached to the contraangle 1 0, andonce the drill bit 14 is inserted, the screws 25,26 canbe rotated untilthe difference between these valuesis in corresponding relationship.Alternatively, for standardized length burrs and given thicknessapertured plate annular disk and lock screw collar, it will also be seenthat the degree of penetration can be .setbeforethe assembly is affixedto the contraangle by making those screw adjustments as are necessary inorder that the burr extends beyond the plate by the required amount.

This manner of utilizing a precisely gauged, positive stop constructionfor use in contraangle drillingoffers a substantial improvement overpresent trial and error techniques in making root canal cuts. Oftentimesemployed arrangements utilizing appropriate thickness rubber washers asbearing surfacesto limitthedepth of penetration suffer the disadvantageof notproviding a strong enough surface to limit morethan th e .desiredextension, but also exhibit the tendency to revolve with the rotatingdrill, thereby reducing the stability and correctness of the overalloperation. Withthe present invention, on the other hand, theadjustmentofthe screws to vary the separation between the annular diskand the apertured plate-of either metalor plasticfabrications-accurately restricts the extension of the burrinto thetooth being prepared, in. providing both depth stop and gaugeoperations.

While there has been described what is considered to be a preferredembodiment of the present invention, it will be, appreciated thatmodifications maybe made by those skilled in the art without departing.from the scope of the teachings herein of using both areferencemeasuring surface and a separate bearing surface to control .the degreeof cut takenby a dental -:drill. Its usage in post and pinreconstructions will-also be readily apparent.

What is claimed is: 1. A combination depth stop and gauge assembly for adental drill comprising:

an annular disk adapted for securement to the housing of said drill andcapable of accepting a burr extending from a spindle thereof;

an apertured plate co-axially aligned with said annular disk andconfigured to receive said burr from said spindle;

and means linking said annular disk and said apertured plate andarranged to move one of said disk and plate axially with respect to theother, for controlling the extent to which said burr protrudes throughsaid annular disk and beyond said apertured plate, with said annulardisk providing a reference measuring surface for the extension of saidburr and with said apertured plate providing a separate bearing surfaceto control the degree of cut taken by said burr.

2. The combination of claim 1 wherein each of said annular disk andapertured plate incorporate thereon a plurality of threaded holes andwherein said lastmentioned means include a like number of adjustablescrews linking said holes and rotatable therein to move said aperturedplate towards and away from said annular disk.

3. The combination of claim 2 wherein each of said screws is rotatablein a clockwise direction to move said apertured plate towards saidannular disk and lengthen the extent to which said burr protrudesthrough said disk and beyond said plate and wherein each of said screwsis rotatable in a counter-clockwise direction to move said aperturedplate away from said annular disk and shorten the extent to which saidburr protrudes through said disk and beyond said plate.

4. The combination of claim 3 for use with a dental drill of the typewherein a lock screw collar is employed to maintain the spindle and burrin correct alignment relative to said housing and wherein said annulardisk is secured to said housing by means of said lock screw

1. A combination depth stop and gauge assembly for a dental drillcomprising: an annular disk adapted for securement to the housing ofsaid drill and capable of accepting a burr extending from a spindlethereof; an apertured plate co-axially aligned with said annular diskand configured to receive said burr from said spindle; and means linkingsaid annular disk and said apertured plate and arranged to move one ofsaid disk and plate axially with respect to the other, for controllingthe extent to which said burr protrudes through said annular disk andbeyond said apertured plate, with said annular disk providing areference measuring surface for the extension of said burr and with saidapertured plate providing a separate bearing surface to control thedegree of cut taken by said burr.
 2. The combination of claim 1 whereineach of said annular disk and apertured plate incorporate thereon aplurality of threaded holes and wherein said last-mentioned meansinclude a like number of adjustable screws linking said holes androtatable therein to move said apertured plate towards and away fromsaid annular disk.
 3. The combination of claim 2 wherein each of saidscrews is rotatable in a clockwise direction to move said aperturedplate towards said annular disk and lengthen the extent to which saidburr protrudes through said disk and beyond said plate and wherein eachof said screws is rotatable in a counter-clockwise direction to movesaid apertured plate away from said annular disk and shorten the extentto which said burr protrudes through said disk and beyond said plate. 4.The combination of claim 3 for use with a dental drill of the typewherein a lock screw collar is employed to maintain the spindle and burrin correct alignment relative to said housing and wherein said annulardisk is secured to said housing by means of said lock screw collar.